1. Field of the Invention
The present invention relates generally to thermal management devices used for dissipating heat from heat sources such as electronic components and other devices. More particularly, the invention relates to active heat sinks.
2. Description of Related Art
Thermal management devices such as heat sinks are widely used in computers, projection systems, televisions and other devices that produce unwanted heat. Unwanted heat is produced, e.g., in computers by inefficiencies in electronic components such as microprocessors and other integrated circuits.
As integrated circuits and other electronic devices are made smaller and designed to operate at increasingly higher processing speeds, they generate increasing amounts of unwanted heat during operation. Electronic components typically operate efficiently only under a certain range of threshold temperatures. Excessive heat generated during operation can harm device performance and reliability and can cause system failure. Thermal management has accordingly become an increasingly important element in the design of electronic products.
Heat sinks are typically used to dissipate heat from the surface of electronic components to a cooler environment, usually ambient air. The heat transfer rate from heat source surfaces directly to the surrounding air is typically poor. A heat sink seeks to increase the heat transfer efficiency primarily by increasing the surface area that is in direct contact with the air. This allows more heat to be dissipated and thereby lowers the device operating temperature.
Heat sinks used for cooling electronic components typically include a thermally conductive baseplate that interfaces directly with the device to be cooled and a set of plate fins extending from the baseplate. The fins increase the surface area that is in direct contact with the air, and thereby increase the heat transfer efficiency between the heat source and ambient air.
Active heat sinks are heat sinks equipped with air handling devices (such as axial fans and blowers) for forcing airflow across the surfaces of the heat sink fins. The airflow further increases heat transfer from the fins to the surrounding air.